By IAN TATTERSALL

o doubt about it: the human mind is one of nature's most remarkable products, if not by a long shot the most remarkable of all. And one of the mind's most singular attributes seems to be a deeply ingrained urge to tell stories, not least about itself and its own origins. For evidence of this one need look no farther than the raft of recent books, mostly by authors calling themselves ''evolutionary psychologists,'' that purport to explain every detail of human behavior by reference to the ''ancestral environment'' within which they suppose our minds and behaviors evolved. No matter how odd our behaviors may look today, it is claimed, they make sense in terms of our hunter-gatherer ancestry. It's just that the world has changed so fast that our genes have been unable to keep up.

Geoffrey Miller, an American cognitive psychologist who teaches at University College, London, falls broadly within the evolutionary psychology camp, but with a difference. Your run-of-the-mill evolutionary psychologist is a committed Neo-Darwinian, for whom evolution consists of little if anything more than the gradual but continuous action of natural selection in ancestor-descendant lineages of organisms. The idea behind natural selection, of course, is that populations will tend to change over time because some heritable features of the individuals constituting them will be more conducive than others to their possessors' successful survival and reproduction. Accordingly, advantageous features will inexorably become commoner in the population, at the expense of less favorable characteristics. In this view, evolution is essentially a slow process of ''fine-tuning'' of organisms to and by their environments; and it provides a perfect foil for reductionist storytelling, since with enough imagination almost any characteristic of an organism can be identified as an ''adaptation'' with a distinctive role to play in the evolutionary scenario.

Miller, however, does not stop there. In ''The Mating Mind: How Sexual Choice Shaped the Evolution of Human Nature'' he begins by arguing that selection among living organisms has two distinct components: natural selection, which arises from competition among individuals for survival, and sexual selection, which is a result of competition for reproductive success. Sexual selection is a concept introduced by Darwin in 1871 to explain such apparently bizarre natural phenomena as male peacocks' extravagant tails. Economically, Darwin could only see these structures as a hindrance, which they certainly are. However, as sexual attractants he believed that they could be explained by female choice; and experiments do seem to have confirmed that female peacocks prefer males with exaggerated plumage.

Why females should wish their males to be thus encumbered is, of course, another question. The general assumption is that such extravagances are ''fitness indicators'' signaling that their possessors are biologically sound and a good choice as partners in the production of high-quality offspring. In some cases this is plausible; and most evolutionary biologists, including those who recognize that the survival/reproduction dichotomy is more than somewhat arbitrary, would agree that at least some of the varieties of sexual ornamentation and behavior abounding in nature may be attributable to mate choice.

So far, so good. But Miller goes far beyond this, ultimately proposing that almost every conceivable human characteristic is a fitness indicator, or at least a result of mate choice. A lot of this is quite ingenious stuff. Why do human females have prominent breasts? Not, apparently, as direct sex attractants. No, it turns out that symmetry of bodily structure is a fitness indicator, and symmetry is more easily detectable among large breasts than small ones. What's more, the pertness of these appendages in young women advertises the period of maximum reproductive effectiveness -- said to be an advantage that outweighs the later penalties of gravity, which warn males off.

Here the sexual selection is made through male choice, but Miller makes a broadly similar argument concerning male penis size through female preference. As with all fine-tuning stories, however, an unresolved question lurks in these and other examples: why does variety persist? After millions of years of unrelenting selection, why don't all women have large breasts and all men long penises?

But by now such exegeses of human bodily structure are in any event a pretty hackneyed genre. Miller's main claim to our attention lies in his assertion that ''the human mind's most distinctive features, such as our capacities for language, art, music, ideology, humor and creative intelligence,'' are due more or less exclusively to mate choice. With his highly mechanistic view of evolution, Miller has to construe art as a puzzle for evolutionary biologists since this activity does not serve any obvious utilitarian function. We are assured, however, that all falls into place when we think in terms of sexual selection. For art, it turns out, is part of the ''extended phenotype'' of human beings: it is one of those characteristics that, while not being physical, still affect individual reproductive success.

Indeed, it seems that the very existence of art is enough to demonstrate that it is a fitness indicator. So, if individuals who create outstanding art are more successful at attracting mates than those who don't (as ''proved,'' for instance, by Picasso, who fathered more than the average number of children), then it seems inevitable that art will become incorporated into the behavioral repertory of the species. Similarly, Miller claims that moral excellence, while not directly affecting survival, has strong ''courtship benefits,'' though of course the example of Picasso doesn't help much here. Miller himself, by the way, seems to be a very decent person, spending a lot of time explaining why people are nice to each other, love each other, speak to each other and so forth. And there is no denying that this is a welcome change from a lot of evolutionary psychology, which is devoted to showing in fundamentalist Neo-Darwinian fashion just why our species is in many ways so appalling. Yet somehow, it's all rather empty when we discover in the end that virtually every aspect of human behavior and cognitive function can be reduced to a form of sexual display. Might there not be a bit more to it than that?

Miller is sensitive to the charge of reductionism, and tries to anticipate it by agreeing that ''there are serious problems with biological reductionism in the sense of trying to account for all of human nature in terms of the survival of the fittest.'' Absolutely. But why he thinks that the ''free market of sexual choice'' is any less beset by problems is less clear. For while it makes storytelling much easier to speak
of the evolution of characteristics -- strength, beauty, aggression, smartness, kindness -- that might in principle be modified by mate choice or by any other putative evolutionary mechanism, the reality is distinctly different. Such characteristics are not disembodied attributes that can somehow be tracked individually over the eons, each having its own independent story. Every characteristic you can name is inextricably embedded in individual organisms, and organisms are enormously complex entities, in which huge numbers of characteristics coexist and are genetically interlinked. And in the real world natural selection can only vote up or down on the whole organism, not on its individual components. Either the entire organism succeeds, or the whole thing goes down the evolutionary drain.

Similarly with mate choice: no matter how much a potential mate might admire your intelligence, for example, he or she might think twice about you if you lack bodily coordination or adequate social skills. We choose whole individuals to mate with, warts and all, and we also have no reliable way of predicting how our genetically unique offspring will turn out. Further, every individual belongs to a population, and that population to a species. Those species and populations are also out there competing in nature with similar entities; and the excellence of your adaptations as an individual will count for little if your population as a whole is being edged out.

Evolution is, thus, a complex multilayered process that is largely immune to the simplicities of the fine-tuning notion. Exegeses like Miller's are often fun to read; and despite its sometimes plodding prose, one can't deny that this book is an impressive work of the imagination. But in the end we are looking here at a product of the storyteller's art, not of science.

Ian Tattersall is a curator at the American Museum of Natural History. His latest books are ''Becoming Human'' and the forthcoming ''Extinct Humans.''